Dry cleaning process



cleaning of fibrous or Patented May 3, 1938 DRY CLEANING PROCESS Arthur A. Levine, Niagara Falls, N.

I. du Pont de Nemours & Company,

to E.

Y., assignor Wilmington, Del., a corporation of Delaware No Drawing.S

1 Claim.

moving any of the color or dye therefrom.

In the prior art there have been disclosed in numerous patents, processes of degreasing textile materials in which organic solvents are used. However, many of these proposed solvents, some of which are now being used commercially, are

unsatisfactory to a greater or less degree in one or more important respects.

It is essential that a satisfactory dry cleaning solvent be relatively stable so that acidity is not developed when the solvent is daily used in commercial apparatus for dry cleaning. Moreover, it must be non-flammable and must have a high solvent power for grease-like stain. Its boiling point must not be too high,- since, in general, a

0 boiling point much higher than l20-l30 C. is

engineer above a few pounds per square inch.

undesirable. This is distillation of the solvent, after use, for the purpose of purifying it, if its boiling point is relatively high a substantial degree of steam pressure.

must be maintained in the distilling. apparatus. The necessity of maintaining a high steam pressure is disadvantageous because of the attendant danger and also because municipal codes generally require the attendanceof a licensed stationary when the steam pressure maintained is One of the greatest difficulties with present dry cleaning solvents is their tendency to bleed or remove dye from some of the fabrics which are frequently encountered in dry cleaning operations. Garments or fabrics fashioned of cellulose acetate, such as those sold commercially under the trade-mark Acele, are usually a source of trouble in most dry cleaning installations employing the solvents now ordinarily used. Thus,

acetate silks tend to bleed or lose quantities of the dye during the dry cleaning operation with solvents such as trichlorethylene, which is one of the solvents now in wide commercial use, and

this means that the garments after dry cleaning because in the subsequent Application Mayl'l, 1935, erial N0. 22,109

are not identical in color with those originally submitted to the dry cleaner.

Accordingly, it is one of the objectsof this invention to utilize a novel dry cleaning solvent for the cleaning of textile fabrics which will effect 5 cleansing without injuring the fabrics or causing color bleeding in any fabric now used in garments. Another object of this invention is to utilize 1,1,2-trichlorpropene-1, either alone or in admixture with other solvents in the fabrics such as wool, viscose, acetate silk, silk, -linen, cotton, etc.

Still another object of this invention is to employ the novel dry cleaning solvent 1,1,2-chlorcleaning of textile 10 propene- 1, having a boiling point of about 118 C., 5

either alone or in admixture with other materials in the removal of spots and stains from fabrics and garments. This practice is commercially called spotting.

As indicated, the compound CI-Ia.CC1=CCl2 may 20 be employed either alone or in admixture with other solvents. particularly the chlorinated hydrocarbons such as carbon tetrachloride and trichlorethylene. It is less volatile than many chlorinated hydrocarbons chlorethylene and carbon tetrachloride now used in dry cleaning, and has therefore less physiological action on persons who may come in contact with its vapors. It is completely uninflame such as ethylene dichloride, tri- 2 mable and does not form an explosixe mixture 30 with air or other gases.

In practicing my invention I immerse or contact in some similar manner fibrous materials, such as clothing or textile fabrics, in a bath consisting in whole or in substantial part of 1,1,2- trichlorpropene-l. After treatment of the fabric or garment it is removed from the bath and heated air may be used to remove the adhering solvent. In this way the time required for the evaporation of the excess solvent in drying the 40 fabric, which may tend to be somewhat greater in view of the lower volatility of the compound, maybe much less than the time ordinarily required for atmospheric drying.

In spotting,1,1,2-trichlorpropene-Leither alone 45 or in admixture with hydrocarbon fractions such as naphtha, benzene, or in admixture with chlorinated hydrocarbons such as trichlorethylene and beta-trichlorethane, may be dropped in small droplets on the spots which are to be removed. 50

The spots are then rubbed with the solvent until the greasy material has gone into solution in the spotting agent. The solvent may then be allowed to evaporate and the, spot will have been re-: moved.

pene-l in dry cleaning, the following may be given:

Example 1 Cellulose acetate fabrics dyed a mauve color were immersed in a bath consisting of pure 1,1,2-trichlorpropene-1. The temperature was maintained at about 60 C. and the fabrics were permitted to remain in the bath for a few minutes.

When removed from the bath, it was found that the acetate silk had been completely cleaned. No change was observable in the color when compared with a portion of the fabric which had not been dry cleaned. It is thus clearly evident that objectionable fading or loss in color does not occur even when acetate silks are immersed in this solvent.

' Example 2 maintained at room temperature and used in a 28- small dry cleaning machine for the dry cleaning of various garments fashioned of difierent fabrics.

The dry cleaning operations were entirely satisfactory and none of the fabrics was in any respect damaged. Although many of the garments were made of acetate silk, evidences of dye bleeding or loss of color were entirely absent.

isfactorily cleaned.

As examples of the use of 1,1,2-trichlorpro-v Example 3 A mixture consisting of 70% of 1,1,2-trichlor propene-l and 30% of trichlorethylene was placed in a small laboratory dry cleaning machine and used for the dry cleaning of various 5 garments. The bath was maintained at a temperature of about 50 C. and the fabrics were permitted to remain immersed in the liquid for a. few minutes.

Subsequent to the immersion, the fabrics were dried by the use of a current of heated air. At the conclusion of the drying operation the garments were examined for evidences of damage such as loss of color due to dye bleeding. Although many of the garments were formed of acetate silk, which is always diflicult to dry clean without dye bleeding, evidences of loss in color were entirely absent. The fabrics were very sat- The various details given in the preceding examples are to be considered as illustrative and not as restrictive. 'The invention is not to be limited to precise conditions and its scope is to be determined solely from the appended claim.

I claim:-

In a process for the dry-cleaning of fabrics composed at least in part of cellulose acetate, the step which comprises contacting said fabrics with a dry-cleaning liquid composition comprising a major proportion of 1,1,2-trichlorpropene-1.

ARTHUR A. LEVINE. 

